The overall objective is to investigate and precisely delineate the B and T lymphocyte, macrophage and other cell populations and their constituent subsets that a) normally populate the ocular adnexa (orbit, conjunctiva, and eyelids); b) participate in the ocular adnexal acute and chronic inflammatory diseases of immune-associated pathogenesis; and c) comprise the benign and malignant ocular adnexal lymphoproliferative disorders. We shall utilize a series of molecular genetic assays, principally Southern and Northern blot hybridization and polymerase chain reaction, to detect the presence and patterns of clonal immunoglobulin variable region gene family usage among the ocular adnexal monoclonal B cell lymphomas. The results will be compared with the results derived from parallel studies of systemic nodal B cell lymphomas. These studies will allow us to 10 determine the molecular profile of the ocular adnexal monoclonal B cell lymphomas at the DNA and RNA level. We shall utilize these same molecular genetic assays to investigate the occult monoclonal and oligoclonal B cell populations that we previously demonstrated to be frequently present in the ocular adnexal lymphoid hyperplasias and also all prior, concurrent and subsequent ocular adnexal and/or systemic nodal lymphoproliferative disorders occuring in the same patients. These studies will allow us to 2) determine the pathogenetic relationship between lymphoid hyperplasia and malignant lymphoma in the ocular adnexa. We shall employ a recently developed novel PCR based assay to 3) determine the incidence of minimal disease spread beyond the ocular adnexa and its clinical relevance for the management, therapy and outcome of patients with ocular adnexal lymphoid proliferations. We shall utilize one and two color immunohistochemical staining techniques in conjunction with a panel of monoclonal antibodies capable of detecting antigens resistent to formalin-fixation and paraffin- embedding to identify mononuclear cell populations in the ocular adnexal inflammatory diseases. The cell populations present at each stage of the natural history of these diseases will be delineated and the results correlated with the clinical and histopathologic features of the disease processes. This will allow us to 4) delineate the clinical, histopathologic, and immunologic characteristics of the immune-associated inflammatory diseases occurring in the ocular adnexa. Finally, we shall employ molecular genetic techniques to investigate the ocular adnexal inflammatory diseases for the presence of multiple viruses which may conceivably play an etiologic role in their pathogenesis. This will allow us to 5) investigate the etiology and pathogenesis of the inflammatory diseases of the ocular adnexa.